The C128 had various chips to display different kinds of graphics that man just stuck to the standard 40 column text display for “ease of use” and let their software handle the rest. To appreciate why these modes existed one had to understand what was happening behind the scenes. Here are the various modes and … Read more
The C64 can display two sets of fonts: either a combination of upper case and lower case letters (good for any kind of text), or a combination of upper case letters and graphics (default), known as PETSCII characters. On a Real Device In direct mode you can switch between the two by pressing CBM+SHIFT (i.e. … Read more
To set the background colour on your beloved old C64 (and C128 in 40 column mode) you have to POKE the colour value into two registers, one for the background and one for the border. The poor little guy only had 16 colour values, 0 for black, 1 for white, etc. To change the background … Read more
Sometimes it’s helpful to store large amounts of data on the disk rather than keep in it memory. Consider adventure games for example: you could add room descriptions to your listing and later read it into memory – but this would double the amount of memory you really need to keep the data. Since there’s … Read more
The 1541 Floppy Drive was equipped with its own MOS 6502 chip and was therefore capable of understanding and executing its own commands (to format the disk, copy files, erase files, etc). The idea was that it could operate autonomously without the attached C64 to get involved – revolutionary at the time. They were called … Read more
I must admit it’s been a while since I’ve loaded files from a C64 and the 1541 Floppy Drive – let alone save programs back to disk. Here’s a quick reference how we did things 30 years ago: Opening Files The C64 BASIC v2 did not have built-in commands for talking to the drive. Instead, … Read more
